For example, a liquid crystal panel used for a liquid crystal display device such as a liquid crystal television set does not emit light by itself, and therefore, requires a separate backlight unit as a lighting device. The known backlight unit is installed on the back side of a liquid crystal panel (side opposite to a display surface) and includes a lot of light sources (for example, LEDs).
Such backlight unit is adapted to obtain white light by combining LEDs of plural colors such as a blue LED, a red LED and a green LED. However, since the LED of each color has larger variation in both chromaticity and brightness than other light sources such as a cold cathode tube, when the LED are arranged in a random manner, uneven color and uneven brightness can occur. Thus, Patent Document 1 describes a device adapted to suppress uneven color and uneven brightness while using the LEDs as light sources. A plurality of units each emitting white light from, for example, one red LED, one blue LED and two green LEDs are arranged on a wiring board to configure light source devices. In each light source device, a first green LED and a second green LED that are different from each other in chromaticity or brightness are arranged in a zigzag manner, and adjacent light source devices are inverted from each other by 180 degrees. As a result, since the first green LED and the second green LED are adjacent to each other in the aligning direction of the light source devices, the adjacent light source devices can average green chromaticity or brightness, thereby suppressing uneven color and uneven brightness.